Substrate processing apparatus for inspecting processing history data

ABSTRACT

During a series of processes performed on a substrate in a substrate processing apparatus, processing history data containing items such as transport time, processing time, plate temperature, revolution per minute of spin motors and flow rate of solutions is obtained for each substrate. When a substrate with a process defect is detected in an inspection block, the processing history data on that substrate is compared with reference data. A processing unit or transport robot in which processing history data falls outside a predetermined range set as the reference data is judged as abnormal, whereby a defective processing unit or defective transport robot is identified. Thus provided is a substrate processing apparatus capable of identifying a defective processing unit or defective transport robot quickly and accurately.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a substrate processing apparatus in which transport robots transport semiconductor substrates, glass substrates for liquid crystal displays, glass substrates for photomasks, substrates for optical disks or the like (hereinafter briefly referred to as “substrates”) to a plurality of processing units each for performing a predetermined process such as photolithography on such substrates.

2. Description of the Background Art

As is well known, products such as semiconductors and liquid crystal displays are manufactured by performing a series of processes including cleaning, resist coating, exposure, development, etching, formation of interlayer dielectric films, thermal processing, dicing and the like, on the above-described substrates. Widely used as a so-called coater/developer is a substrate processing apparatus in which a plurality of processing units for performing, for example, among the series of processes, resist coating, development and their associated thermal processes, respectively, are incorporated, and transport robots circularly transport substrates between the respective processing units, so that the substrates are subjected to a series of photolithography processes.

In accordance with the recent demand for higher accuracy in apparatus control and processing accuracy of such substrate processing apparatus, it is desired to keep track of various types of measured data obtained during actual processes such as processing time, processing temperature, revolution per minute of motors and flow rate of chemical solutions, as processing history data. Accordingly, techniques for collecting various types of data during processes performed on substrates using a control system installed in a substrate processing apparatus, to thereby accumulate the collected data as the processing history are proposed in, for example, Japanese Patent Application Laid-Open Nos. 2002-343694 and 2002-280278.

Turning to the case in which a substrate with a process defect occurs in the above-described substrate processing apparatus, an operator of the apparatus conventionally makes an inspection on the apparatus to make clear the cause of such defect, to thereby identify a processing unit in which abnormal processing has been conducted. Identifying a defective processing unit requires a great deal of time, and it is an extremely difficult operation particularly for an inexperienced operator, causing at worst a problem in that a defective processing unit cannot be identified accurately.

SUMMARY OF THE INVENTION

The present invention is directed to a substrate processing apparatus for transporting a substrate to a plurality of processing units by transport robots to perform a predetermined process on the substrate.

According to the present invention, the substrate processing apparatus comprises: a receiving element for receiving processing history data obtained during the predetermined process; and a defective processing unit identifying element for judging whether or not the processing history data received by the receiving element falls within a predetermined range which is previously set, to thereby identify a defective one of the processing units or a defective one of the transport robots.

A defective processing unit or defective transport robot is identified by obtaining processing history data during the predetermined process on a substrate and judging whether or not the processing history data falls within a predetermined range which is previously set. Thus, a defective processing unit or defective transport robot can automatically be identified quickly and accurately regardless of operator's skills.

Preferably, the substrate processing apparatus further comprises an inspecting element for making an inspection on a substrate which has undergone the predetermined process or on the way of the predetermined process. When a substrate with a process defect is detected by the inspecting element, the defective processing unit identifying element identifies a defective one of the processing units or a defective one of the transport robots on the basis of the processing history data obtained when the predetermined process is performed on the substrate.

When a substrate with a process defect is detected by the inspecting element, a defective processing unit or defective transport robot is identified on the basis of processing history data obtained during processes performed on that substrate. Thus, a processing unit or transport robot which has caused a process defect can be identified quickly and accurately.

More preferably, in the substrate processing apparatus, when a substrate with a process defect is detected by the inspecting element, the defective processing unit identifying element assigns priority to making a judgment on processing history data on one of the processing units and one of the transport robots previously associated with the details of the process defect over making a judgment on processing history data on another one of the processing units and another one of the transport robots.

A processing unit or transport robot which has caused a process defect can be identified quickly and accurately.

It is therefore an object of the present invention to provide a substrate processing apparatus capable of identifying a defective processing unit or defective transport robot quickly and accurately.

These and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a substrate processing apparatus according to a first preferred embodiment;

FIG. 2 is a front view of a solution processing part of the substrate processing apparatus shown in FIG. 1;

FIG. 3 is a front view of a thermal processing part of the substrate processing apparatus shown in FIG. 1;

FIG. 4 illustrates a peripheral structure of substrate rest parts of the substrate processing apparatus shown in FIG. 1;

FIGS. 5A and 5B are explanatory views of a transport robot of the substrate processing apparatus shown in FIG. 1; and

FIG. 6 is a block diagram schematically showing a control mechanism of the substrate processing apparatus shown in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, preferred embodiments of the present invention will be described in detail in reference to the accompanying drawings.

First Preferred Embodiment

FIG. 1 is a plan view of a substrate processing apparatus according to a first preferred embodiment. FIG. 2 is a front view of a solution processing part of the substrate processing apparatus. FIG. 3 is a front view of a thermal processing part. FIG. 4 illustrates a peripheral structure of substrate rest parts. FIGS. 1 to 4 include an XYZ rectangular coordinate system which defines the direction of the Z axis as the vertical direction and the X-Y plane as the horizontal plane.

The substrate processing apparatus according to the present embodiment is an apparatus for coating a substrate such as a semiconductor wafer with an antireflective film and a photoresist film as well as for conducting a development process on a substrate with a pattern transferred thereto by exposure. Substrates to be processed by the substrate processing apparatus of the present invention are not limited to semiconductor wafers, but may be glass substrates for liquid crystal displays, or the like. Processes conducted by the substrate processing apparatus of the present invention are not limited to formation of a coated film and development, but may be etching and cleaning.

The substrate processing apparatus according to the present embodiment comprises six processing blocks arranged in parallel: an indexer block 1; a BARC (Bottom Antireflective Coating) block 2; a resist coating block 3; a development processing block 4; an interface block 5; and an inspection block IB. An exposure apparatus (stepper) which is an external apparatus provided separately from the substrate processing apparatus is connected to the interface block 5.

The indexer block 1 comprises a carrier table 11 for placing thereon a plurality of (in the present embodiment, four) carriers C in adjacent relation and a substrate transport mechanism 12 for taking out an unprocessed substrate W from each of the carriers C and storing a processed substrate W into each of the carriers C. The substrate transport mechanism 12 includes a movable table 12 a movable horizontally along the carrier table 11 (along the Y axis), and a holding arm 12 b for holding a substrate W in a horizontal position is mounted on the movable table 12 a. The holding arm 12 b is movable up and down over the movable table 12 a (along the Z axis), pivotable within a horizontal plane and movable back and forth in the direction of the pivot radius. The substrate transport mechanism 12 can thereby moves the holding arm 12 b to get access to each of the carriers C to take out an unprocessed substrate W therefrom and to store a processed substrate W therein. The carriers C may be of any of the following types: a FOUP (front opening unified pod) for storing substrates W in an enclosed or sealed space, an SMIF (standard mechanism interface) pod and an OC (open cassette) which exposes stored substrates W to the open air.

The BARC block 2 is provided adjacently to the indexer block 1. Between the indexer block 1 and BARC block 2, a partition 13 for closing off the communication of atmosphere between the blocks is provided. Two substrate rest parts PASS1 and PASS2 each for placing a substrate W thereon to transfer the substrate W between the indexer block 1 and BARC block 2 are provided in stacked relation to extend through this partition 13.

The upper substrate rest part PASS1 is used to transfer a substrate W from the indexer block 1 to the BARC block 2. The substrate rest part PASS1 is provided with three support pins, and the substrate transport mechanism 12 of the indexer block 1 places an unprocessed substrate W taken out from a carrier C on the three support pins of the substrate rest part PASS1. Then, a transport robot TR1 of the BARC block 2 which will be described later receives the substrate W placed on the substrate rest part PASS1. The lower substrate rest part PASS2 is used to transfer a substrate W from the BARC block 2 to the indexer block 1. The substrate rest part PASS2 is also provided with three support pins, and the transport robot TR1 of the BARC block 2 places a processed substrate W on the three support pins of the substrate rest part PASS2. Then, the substrate transport mechanism 12 receives the substrate W placed on the substrate rest part PASS2 to store the substrate W in a carrier C. Substrate rest parts PASS3 to PASS12 which will be described later have the same construction as the substrate rest parts PASS1 and PASS2.

The substrate rest parts PASS1 and PASS2 both partly extend through part of the partition 13, and are each provided with an optical sensor (not shown) for detecting the presence or absence of a substrate W. In response to detection signals from the respective sensors, it is judged whether or not the substrate transport mechanism 12 and transport robot TR1 of the BARC block 2 are in a state of readiness to transfer and receive a substrate W to and from the substrate rest parts PASS1 and PASS2.

Next, the BARC block 2 will be described. The BARC block 2 is a processing block for forming an antireflective film under a photoresist film in order to reduce standing waves or halation occurring during exposure. The BARC block 2 comprises an underlying film coating processor BRC for coating the surface of a substrate W with the antireflective film, two thermal processing towers 21, 21 each for performing a thermal process associated with the coating of the antireflective film and the transport robot TR1 for transferring and receiving a substrate W to and from the underlying film coating processor BRC and the thermal processing towers 21, 21.

In the BARC block 2, the underlying film coating processor BRC and the thermal processing towers 21, 21 are arranged opposite to each other with the transport robot TR1 interposed therebetween. Specifically, the underlying film coating processor BRC is positioned on the front side of the apparatus, and the two thermal processing towers 21, 21 are positioned on the rear side of the apparatus. A thermal barrier not shown is provided on the front side of the thermal processing towers 21, 21. Arranging the underlying film coating processor BRC and the thermal processing towers 21, 21 at a distance and providing the thermal barrier prevent the underlying film coating processor BRC from suffering from the thermal effect caused by the thermal processing towers 21, 21.

Referring to FIG. 2, the underlying film coating processor BRC includes three coating processing units BRC1 to BRC3 having the same construction, arranged in stacked relation in ascending order. Hereinafter, where there is no need to distinguish the three coating processing units BRC1 to BRC3 from one another, these units will collectively be referred to as the underlying film coating processor BRC. Each of the three coating processing units BRC1 to BRC3 is provided with a spin chuck 22 for rotating a substrate W within an almost horizontal plane while holding the substrate W in an almost horizontal position under suction, a discharging nozzle 23 for discharging a coating solution for the antireflective film onto the substrate W held on the spin chuck 22, a spin motor (not shown) for rotatably driving the spin chuck 22, a cup (not shown) for surrounding the substrate W held on the spin chuck 22, and the like.

Referring to FIG. 3, one of the thermal processing towers 21 located close to the indexer block 1 is provided with six hot plates HP1 to HP6 for heating a substrate W to a predetermined temperature and cooling plates CP1 to CP3 for cooling the heated substrate W to a predetermined temperature and maintaining the substrate W at the predetermined temperature. In this one of the thermal processing towers 21, the cooling plates CP1 to CP3 and the hot plates HP1 to HP6 are stacked in ascending order. On the other hand, in the other one of the thermal processing towers 21 located away from the indexer block 1, three adhesion promotion processing units AHL1 to AHL3 for thermally processing a substrate W in an atmosphere of HMDS (hexamethyl disilazane) vapor for the purpose of promoting the adhesion of a resist film to the substrate W are stacked in ascending order. The locations indicated by the cross marks (x) in FIG. 3 are occupied by a piping and wiring section and a reserve empty space.

As described, stacking the coating processing units BRC1 to BRC3 and thermal processing units (hot plates HP1 to HP6, cooling plates CP1 to CP3 and adhesion promotion processing units AHL1 to AHL3) in multistage can reduce the footprint of the substrate processing apparatus. Further, providing the two thermal processing towers 21, 21 in parallel brings advantages of facilitating maintenance of the thermal processing units and removing the necessity of extending duct piping and a power supply necessary for the thermal processing units to a very high position.

FIGS. 5A and 5B are explanatory views of the transport robot TR1. FIG. 5A is a plan view and FIG. 5B is a front view of the transport robot TR1. The transport robot TR1 is provided with two holding arms 6 a and 6 b arranged one above the other in close contact with each other, for supporting a substrate W in an almost horizontal position. The holding arms 6 a and 6 b each have a C-shaped distal end portion in a plan view, and a plurality of pins 7 projecting inwardly of the inner side of the C-shaped distal end portions hold the periphery of a substrate W from underneath.

A base 8 of the transport robot TR1 is fixedly provided on a base of the apparatus (apparatus frame). On the base 8, a guide shaft 9 c is provided in a standing manner, and a screw shaft 9 a is rotatably supported in a standing manner. A motor 9 b is also fixedly provided on the base 8 for rotatably driving the screw shaft 9 a. Then, the screw shaft 9 a is brought into threaded engagement with an elevating table 10 a, which is slidably movable along the guide shaft 9 c. With such construction, the motor 9 b rotatably drives the screw shaft 9 a, so that the elevating table 10 a is guided along the guide shaft 9 c to move up and down in the vertical direction (along the Z axis).

An arm base 10 b is provided on the elevating table 10 a pivotably about an axis extending in the vertical direction. The elevating table 10 a includes therein a motor 10 c for pivotably driving the arm base 10 b. The above-described two holding arms 6 a and 6 b are arranged one above the other on the arm base 10 b. Each of the holding arms 6 a and 6 b is configured to be movable back and forth independently in the horizontal direction (in the direction of the pivot radius of the arm base 10 b) by means of a sliding drive mechanism (not shown) equipped with the arm base 10 b.

With such construction, as shown in FIG. 5A, the transport robot TR1 moves its two holding arms 6 a and 6 b to independently get access to the substrate rest parts PASS1, PASS2, the thermal processing units provided in the thermal processing towers 21, the coating processing units provided in the underlying film coating processor BRC and the substrate rest parts PASS3 and PASS4 which will be described later, so that a substrate W can be transferred and received to and from these units.

Next, the resist coating block 3 will be described. The resist coating block 3 is sandwiched between the BARC block 2 and inspection block IB. Between the BARC block 2 and resist coating block 3, a partition 25 for closing off the communication of atmosphere between the blocks is provided. The two substrate rest parts PASS3 and PASS4 each for placing a substrate W thereon to transfer the substrate W between the BARC block 2 and resist coating block 3 are arranged in stacked relation to extend through this partition 25. The substrate rest parts PASS3 and PASS4 have the same construction as the above-described substrate rest parts PASS1 and PASS2.

The upper substrate rest part PASS3 is used to transfer a substrate W from the BARC block 2 to the resist coating block 3. That is, a transport robot TR2 of the resist coating block 3 receives a substrate W placed on the substrate rest part PASS3 by the transport robot TR1 of the BARC block 2. The lower substrate rest part PASS4 is used to transport a substrate W from the resist coating block 3 to the BARC block 2. That is, the transport robot TR1 of the BARC block 2 receives a substrate W placed on the substrate rest part PASS4 by the transport robot TR2 of the resist coating block 3.

The substrate rest parts PASS3 and PASS4 both partly extend through part of the partition 25, and are each provided with an optical sensor (not shown) for detecting the presence or absence of a substrate W. In response to detection signals from the respective sensors, it is judged whether or not the transport robots TR1 and TR2 are in a state of readiness to transfer and receive a substrate W to and from the substrate rest parts PASS3 and PASS4. Further, two cooling plates WCP for roughly water-cooling a substrate W are provided in stacked relation under the substrate rest parts PASS3 and PASS4 to extend through the partition 25.

The resist coating block 3 is a processing block for forming the photoresist film on a substrate W coated with the antireflective film in the BARC block 2. In this preferred embodiment, a chemically amplified resist is used as the photoresist. The resist coating block 3 comprises a resist coating processor SC for coating the photoresist film on the antireflective film coated as an underlying film, two thermal processing towers 31, 31 each for performing a thermal process associated with the resist coating and the transport robot TR2 for transferring and receiving the substrate W to and from the resist coating processor SC and the thermal processing towers 31, 31.

In the resist coating block 3, the resist coating processor SC and the thermal processing towers 31, 31 are arranged opposite to each other with the transport robot TR2 interposed therebetween. Specifically, the resist coating processor SC is positioned on the front side of the apparatus, and the two thermal processing towers 31, 31 are positioned on the rear side of the apparatus. A thermal barrier not shown is provided on the front side of the thermal processing towers 31, 31. Arranging the resist coating processor SC and the thermal processing towers 31, 31 at a distance and providing the thermal barrier prevent the resist coating processor SC from suffering from the thermal effect caused by the thermal processing towers 31, 31.

As shown in FIG. 2, the resist coating processor SC includes three coating processing units SC1 to SC3 having the same construction, stacked in ascending order. Hereinafter, where there is no need to distinguish the three coating processing units SC1 to SC3 from one another, these units will collectively be referred to as the resist coating processor SC. Each of the three coating processing units SC1 to SC3 is provided with a spin chuck 32 for rotating a substrate W within an almost horizontal plane while holding the substrate W in an almost horizontal position under suction, a discharging nozzle 33 for discharging a photoresist onto the substrate W held on the spin chuck 32, a spin motor (not shown) for rotatably driving the spin chuck 32, a cup (not shown) for surrounding the substrate W held on the spin chuck 32, and the like.

As shown in FIG. 3, one of the thermal processing towers 31 located close to the indexer block 1 is provided with six heating units PHP1 to PHP6 for heating a substrate W to a predetermined temperature, stacked in ascending order. On the other hand, in the other one of the thermal processing towers 31 located away from the indexer block 1, cooling plates CP4 to CP9 for cooling the heated substrate W to a predetermined temperature and maintaining the substrate W at the predetermined temperature are stacked in ascending order.

Each of the heating units PHP1 to PHP6 is a thermal processing unit having an ordinary hot plate for placing a substrate W thereon and heating the substrate W as well as a temporary substrate rest part for placing a substrate W thereon above the hot plate at a distance and a local transport mechanism 34 (FIG. 1) for transporting a substrate W between the hot plate and temporary substrate rest part. The local transport mechanism 34 is movable up, down, back and forth, and is provided with a mechanism for circulating cooling water for cooling a substrate W on the way of transportation.

The local transport mechanism 34 is positioned on the opposite side of the transport robot TR2 with respect to the hot plate and temporary substrate rest part, that is, on the rear side of the apparatus. The temporary substrate rest part is opened toward both the transport robot TR2 and local transport mechanism 34, while the hot plate is opened only toward the local transport mechanism 34 and closed toward the transport robot TR2. Therefore, to the temporary substrate rest part, both the transport robot TR2 and local transport mechanism 34 are capable of getting access, however, to the hot plate, only the local transport mechanism 34 is capable of getting access.

For transporting a substrate W to each of the heating units PHP1 to PHP6 of such construction, the transport robot TR2 first places a substrate W on the temporary substrate rest part. Then, the local transport mechanism 34 receives the substrate W from the temporary substrate rest part and transports the substrate W to the hot plate, where the substrate W is subjected to a heating process. Upon completion of the heating process on the hot plate, the substrate W is taken out by the local transport mechanism 34 and is transported to the temporary substrate rest part. At this time, the substrate W is cooled by a cooling mechanism provided for the local transport mechanism 34. Thereafter, the substrate W transported to the temporary substrate rest part which has undergone the thermal process is taken out by the transport robot TR2.

As described, in each of the heating units PHP1 to PHP6, the transport robot TR2 only transfers and receives a substrate W to and from the temporary substrate rest part at room temperature, not to and from the hot plate. This can prevent a rise in temperature of the transport robot TR2. Further, the hot plate is opened only toward the local transport mechanism 34, which can prevent the transport robot TR2 and resist coating processor SC from suffering from the adverse effect which would be caused by hot atmosphere leaked out from the hot plate. The transport robot TR2 transfers and receives a substrate W directly to and from the cooling plates CP4 to CP9.

The transport robot TR2 has exactly the same construction as the transport robot TR1. Accordingly, the transport robot TR2 moves its two holding arms to independently get access to the substrate rest parts PASS3, PASS4, the thermal processing units provided in the thermal processing towers 31, the coating processing units provided in the resist coating processor SC and the substrate rest parts PASS5 and PASS6 which will be described later, so that a substrate W can be transferred and received to and from these units.

Next, the inspection block IB will be described. The inspection block IB is sandwiched between the resist coating block 3 and development processing block 4. Between the resist coating block 3 and inspection block IB, a partition 35 for closing off the communication of atmosphere between the blocks is provided. The two substrate rest parts PASS5 and PASS6 each for placing a substrate W thereon to transfer the substrate W between the resist coating block 3 and inspection block IB are arranged in stacked relation to extend through this partition 35. The substrate rest parts PASS5 and PASS6 have the same construction as the above-described substrate rest parts PASS1 and PASS2.

The upper substrate rest part PASS5 is used to transfer a substrate W from the resist coating block 3 to the inspection block IB. That is, a transport robot TR5 of the inspection block IB receives a substrate W placed on the substrate rest part PASS5 by the transport robot TR2 of the resist coating block 3. The lower substrate rest part PASS6 is used to transport a substrate W from the inspection block IB to the resist coating block 3. That is, the transport robot TR2 of the resist coating block 3 receives a substrate W placed on the substrate rest part PASS6 by the transport robot TR5 of the inspection block IB.

The substrate rest parts PASS5 and PASS6 both partly extend through part of the partition 35, and are each provided with an optical sensor (not shown) for detecting the presence or absence of a substrate W. In response to detection signals from the respective sensors, it is judged whether or not the transport robots TR2 and TR5 are in a state of readiness to transfer and receive a substrate W to and from the substrate rest parts PASS5 and PASS6. Further, two cooling plates WCP for roughly water-cooling a substrate W are provided in stacked relation under the substrate rest parts PASS5 and PASS6 to extend through the partition 35.

The inspection block IB is a processing block for inspecting a substrate W which has undergone a series of photolithography processes or on the way of the processes. The inspection block IB comprises a film thickness measuring unit 80, a line width measuring unit 85, a macro defect inspecting unit 90, an inspection buffer 95 and the transport robot TR5 for transferring and receiving a substrate W to and from these units. The transport robot TR5 has exactly the same construction as the above-described transport robots TR1 and TR2.

As shown in FIG. 2, the film thickness measuring unit 80 is positioned on the front side of the apparatus at the lower stage. The film thickness measuring unit 80 includes a film thickness measuring device 81 for optically measuring the film thickness of the resist which coats a substrate W. The line width measuring unit 85 is positioned on the front side of the apparatus at the upper stage. The line width measuring unit 85 includes a line width measuring device 86 for optically measuring the line width of the pattern transferred to a substrate W which has undergone a development process.

On the other hand, as shown in FIG. 3, the macro defect inspecting unit 90 is positioned on the rear side of the apparatus at the lower stage of the inspection block IB. The macro defect inspecting unit 90 includes a macro defect inspecting device 91 for optically detecting a relatively large defect appeared on a substrate W, e.g., adhesion of particles or nonuniform coating of the resist. The inspection buffer 95 is provided in two rows above the macro defect inspecting unit 90, i.e., on the rear side of the apparatus at the upper stage of the inspection block IB. The inspection buffer 95 includes a cabinet capable of storing a plurality of substrates W in tiers. When a substrate W is subjected to an inspection in any one of the film thickness measuring unit 80, line width measuring unit 85 and macro defect inspecting unit 90, the inspection buffer 95 is used to temporarily store substrates W to be subsequently inspected at these units.

The film thickness measuring unit 80, line width measuring unit 85 and macro defect inspecting unit 90 are not limited to the above-described positions, but the positions may be interchanged.

The transport robot TR5 has exactly the same construction as the transport robot TR1. Accordingly, the transport robot TR5 moves its two holding arms to independently get access to the substrate rest parts PASS5, PASS6, film thickness measuring unit 80, line width measuring unit 85, macro defect inspecting unit 90, inspection buffer 95 and substrate rest parts PASS7 and PASS8 which will be described later, so that a substrate W can be transferred and received to and from these units.

Next, the development processing block 4 will be described. The development processing block 4 is sandwiched between the inspection block IB and interface block 5. Between the inspection block IB and development processing block 4, a partition 45 for closing off the communication of atmosphere between the blocks is provided. The two substrate rest parts PASS7 and PASS8 each for placing a substrate W thereon to transfer the substrate W between the inspection block IB and development processing block 4 are arranged in stacked relation to extend through this partition 45. The substrate rest parts PASS7 and PASS8 have the same construction as the above-described substrate rest parts PASS1 and PASS2.

The upper substrate rest part PASS7 is used to transfer a substrate W from the inspection block IB to the development processing block 4. That is, a transport robot TR3 of the development processing block 4 receives a substrate W placed on the substrate rest part PASS7 by the transport robot TR5 of the inspection block IB. The lower substrate rest part PASS8 is used to transport a substrate W from the development processing block 4 to the inspection block IB. That is, the transport robot TR5 of the inspection block IB receives a substrate W placed on the substrate rest part PASS8 by the transport robot TR3 of the development processing block 4.

The substrate rest parts PASS7 and PASS8 both partly extend through part of the partition 45, and are each provided with an optical sensor (not shown) for detecting the presence or absence of a substrate W. In response to detection signals from the respective sensors, it is judged whether or not the transport robots TR5 and TR3 are in a state of readiness to transfer and receive a substrate W to and from the substrate rest parts PASS7 and PASS8. Further, two cooling plates WCP for roughly water-cooling a substrate W are provided in stacked relation under the substrate rest parts PASS7 and PASS8 to extend through the partition 45.

The development processing block 4 is a processing block for performing a development process on an exposed substrate W. The development processing block 4 comprises a development processor SD for performing a development process by supplying a developing solution onto a substrate W with a pattern transferred thereto by exposure, two thermal processing towers 41, 42 each for performing a thermal process associated with the development process and the transport robot TR3 for transferring and receiving a substrate W to and from the development processor SD and thermal processing towers 41, 42. The transport robot TR3 has exactly the same construction as the above-described transport robot TR1.

As shown in FIG. 2, the development processor SD includes five development processing units SD1 to SD5 all having the same construction, stacked in ascending order. Hereinafter, where there is no need to distinguish these five development processing units SD1 to SD5 from one another, these units will collectively be referred to as the development processor SD. Each of the development processing units SD1 to SD5 is provided with a spin chuck 43 for rotating a substrate W within an almost horizontal plane while holding the substrate W in an almost horizontal position under suction, a discharging nozzle 44 for discharging a developing solution onto the substrate W held on the spin chuck 43, a spin motor (not shown) for rotatably driving the spin chuck 43, a cup (not shown) for surrounding the substrate W held on the spin chuck 43, and the like.

As shown in FIG. 3, the thermal processing tower 41 located close to the indexer block 1 is provided with five hot plates HP7 to HP11 for heating a substrate W to a predetermined temperature and cooling plates CP10 to CP12 for cooling the heated substrate W to a predetermined temperature and maintaining the substrate W at the predetermined temperature. In this thermal processing tower 41, the cooling plates CP10 to CP12 and the hot plates HP7 to HP11 are stacked in ascending order. On the other hand, in the thermal processing tower 42 located away from the indexer block 1, six heating units PHP7 to PHP12 and a cooling plate CP13 are provided in stacked relation. Each of the heating units PHP7 to PHP12 is a thermal processing unit having a temporary substrate rest part and a local transport mechanism, similarly to the heating units PHP1 to PHP6. However, the temporary substrate rest part of each of the heating units PHP7 to PHP12 is opened toward a transport robot TR4 of the interface block 5, but is closed toward the transport robot TR3 of the development processing block 4. In other words, the transport robot TR4 of the interface block 5 is capable of getting access to the heating units PHP7 to PHP 12, while the transport robot TR3 of the development processing block 4 is not. To the thermal processing units provided in the thermal processing tower 41, the transport robot TR3 of the development processing block 4 gets access.

In the thermal processing tower 42, the two substrate rest parts PASS9 and PASS10 for transferring a substrate W between the development processing block 4 and interface block 5 adjacent thereto are arranged one above the other in close contact with each other. The upper substrate rest part PASS9 is used to transfer a substrate W from the development processing block 4 to the interface block 5. That is, the transport robot TR4 of the interface block 5 receives a substrate W placed on the substrate rest part PASS9 by the transport robot TR3 of the development processing block 4. The lower substrate rest part PASS10 is used to transport a substrate W from the interface block 5 to the development processing block 4. That is, the transport robot TR3 of the development processing block 4 receives a substrate W placed on the substrate rest part PASS10 by the transport robot TR4 of the interface block 5. The substrate rest parts PASS9 and PASS10 are each opened toward both the transport robot TR3 of the development processing block 4 and the transport robot TR4 of the interface block 5.

Next, the interface block 5 will be described. The interface block 5 is provided adjacently to the development processing block 4, and transfers and receives a substrate W to and from an exposure apparatus which is an external apparatus provided separately from the substrate processing apparatus of the present invention. The interface block 5 according to the present embodiment comprises a transport mechanism 55 for transferring and receiving a substrate W to and from the exposure apparatus as well as two edge exposure units EEW for exposing the periphery of a substrate W with a photoresist film formed thereon and the transport robot TR4 for transferring and receiving a substrate W to and from the heating units PHP7 to PHP12 provided in the development processing block 4 and the edge exposure units EEW.

As shown in FIG. 2, each of the edge exposure units EEW is provided with a spin chuck 56 for rotating a substrate W within an almost horizontal plane while holding the substrate W in an almost horizontal position under suction, a light irradiator 57 for irradiating light to expose the periphery of the substrate W held on the spin chuck 56, and the like. The two edge exposure units EEW are arranged in stacked relation in the center of the interface block 5. The transport robot TR4 provided adjacently to the edge exposure units EEW and the thermal processing tower 42 of the development processing block 4 has the same construction as the above-described transport robot TR1.

Further, as shown in FIG. 2, a return buffer RBF is provided under the two edge exposure units EEW, and thereunder, the two substrate rest parts PASS11 and PASS12 are arranged in stacked relation. The return buffer RBF is for temporarily storing a substrate W therein upon completion of heating at the heating units PHP7 to PHP12 and cooling at the cooling plate CP13 of the development processing block 4 after the exposure process if the development processing block 4 cannot perform the development process on the substrate W for some trouble. The return buffer RBF includes a cabinet capable of storing a plurality of substrates W in tiers. The upper substrate rest part PASS11 is used to transfer a substrate W from the transport robot TR4 to the transport mechanism 55. The lower substrate rest part PASS12 is used to transport a substrate W from the transport mechanism 55 to the transport robot TR4. To the return buffer RBF, the transport robot TR4 gets access.

As shown in FIG. 2, the transport mechanism 55 has a movable table 55 a movable horizontally along the Y axis, and a holding arm 55 b for holding a substrate W on the movable table 55 a. The holding arm 55 b is movable up and down, pivotable and movable back and forth in the direction of the pivot radius with respect to the movable table 55 a. With such construction, the transport mechanism 55 transfers and receives a substrate W to and from the exposure apparatus, and also transfers and receives a substrate W to and from the substrate rest parts PASS11 and PASS12, and stores and takes out a substrate W in and from a send buffer SBF. The send buffer SBF is for temporarily storing an unexposed substrate W when the exposure apparatus cannot accept the substrate W, and includes a cabinet capable of storing a plurality of substrates W in tiers.

A downflow of clean air is always supplied into the above-described indexer block 1, BARC block 2, resist coating block 3, development processing block 4, interface block 5 and inspection block IB to thereby avoid the adverse effects of raised particles and gas flows upon the processes in the respective blocks. The interior of each of the blocks is held at a slightly positive pressure relative to the external environment to prevent particles and contaminants in the external environment from entering the blocks 1 to 5.

Further, the above-described indexer block 1, BARC block 2, resist coating block 3, development processing block 4, interface block 5 and inspection block IB are parts obtained by mechanically dividing the substrate processing apparatus according to the present embodiment. Each of the blocks is fitted into an individual block-specific frame, and the respective block-specific frames are connected to one another to construct the substrate processing apparatus.

On the other hand, in the present embodiment, the transport of substrates W is effected on the basis of transport control units, different from mechanically divided blocks. In this specification, such transport control units for the substrate transport are referred to as “cells.” Each cell comprises a plurality of processing units for performing a predetermined process on a substrate W and a transport robot for transporting the substrate W to the plurality of processing units. Each of the above-described substrate rest parts serves as an inlet substrate rest part for receiving a substrate W into a cell or an outlet substrate rest part for transporting a substrate W from a cell. The transfer of a substrate W between cells is conducted through the substrate rest parts. In the present specification, the substrate rest parts just for placing a substrate W thereon are included in “processing units” in the sense that a substrate W is to be transported thereto, in addition to-the thermal processing units, coating/development processing units and edge exposure units. The substrate transport mechanism 12 and transport mechanism 55 are included in transport robots as they transport substrates W.

The substrate processing apparatus according to the present embodiment comprises seven cells: an indexer cell; a BARC cell; a resist coating cell; an inspection cell; a development processing cell; a post-exposure bake cell; and an interface cell. The indexer cell includes the carrier table 11 and substrate transport mechanism 12, and as a result has the same construction as the indexer block 1 which is a mechanically divided part. The BARC cell includes the underlying film coating processor BRC, two thermal processing towers 21, 21 and transport robot TR1. This BARC cell also as a result has the same construction as the BARC block 2 which is a mechanically divided part. The resist coating cell includes the resist coating processor SC, two thermal processing towers 31, 31 and transport robot TR2. This resist coating cell also as a result has the same construction as the resist coating block 3 which is a mechanically divided part. The inspection cell includes the film thickness measuring unit 80, line width measuring unit 85, macro defect inspecting unit 90, inspection buffer 95 and transport robot TR5. This inspection cell also as a result has the same construction as the inspection block IB which is a mechanically divided part.

The development processing cell includes the development processor SD, thermal processing tower 41 and transport robot TR3. As described, the transport robot TR3 is incapable of getting access to the heating units PHP7 to PHP12 of the thermal processing tower 42, and therefore the thermal processing tower 42 is not included in the development processing cell. In this respect, the development processing cell differs from the development processing block 4 which is a mechanically divided part.

The post-exposure bake cell includes the thermal processing tower 42 located in the development processing block 4, edge exposure units EEW located in the interface block 5 and transport robot TR4. In other words, the post-exposure bake cell extends from the development processing block 4 to the interface block 5 which are mechanically divided parts. As described, the heating units PHP7 to PHP12 for performing a post-exposure heating process and the transport robot TR4 are included in one cell, which allows an exposed substrate W to be readily transported into the heating units PHP7 to PHP12 for performing a heating process thereon. Such construction is desirable in the case of using a chemically amplified resist that requires a heating process to be performed as soon as possible after transferring a pattern to a substrate W by exposure.

The substrate rest parts PASS9 and PASS10 included in the thermal processing tower 42 are provided for transferring a substrate W between the transport robot TR3 of the development processing cell and the transport robot TR4 of the post-exposure bake cell.

The interface cell includes the transport mechanism 55 for transferring and receiving a substrate W to and from the exposure apparatus which is an external apparatus. This interface cell does not include the transport robot TR4 or edge exposure units EEW, and, in this sense, has a different construction from the interface block 5 which is a mechanically divided part. The substrate rest parts PASS11 and PASS12 provided under the edge exposure units EEW are provided for transferring a substrate W between the transport robot TR4 of the post-exposure bake cell and the transport mechanism 55 of the interface cell.

Next, a control mechanism of the substrate processing apparatus according to the present embodiment will be described. FIG. 6 is a block diagram schematically showing the control mechanism. As shown in the drawing, the substrate processing apparatus of the present embodiment has a three-level control hierarchy including a main controller MC, cell controllers CC and unit controllers. The hardware construction of each of the main controller MC, cell controllers CC and unit controllers is similar to that of a general computer. That is, each of the controllers includes a CPU for performing various operations, a ROM which is a read-only memory for storing a fundamental program, a RAM which is a readable and writable memory for storing various types of information, a magnetic disk for storing a control-dedicated application and data, and the like.

At the first level, one main controller MC is provided in the whole substrate processing apparatus, and is mainly responsible for controlling the whole apparatus, a main panel MP and cell controllers CC. The main panel MP serves as a display of the main controller MC. Various commands can be input to the main controller MC using a keyboard KB. The main panel MP may be a touch panel, so that an input operation to the main controller MC may be carried out through the main panel MP. The main controller MC has a magnetic disk 99, in which processing history data to be described later is stored.

The cell controllers CC at the second level are provided in one-to-one correspondence to the seven cells (indexer cell, BARC cell, resist coating cell, inspection cell, development processing cell, post-exposure bake cell and interface cell). Each of the cell controllers CC is mainly responsible for controlling substrate transport within a corresponding one of the cells and controlling the units. Specifically, transmission of information is performed in such a manner that a cell controller CC corresponding to a cell sends information that a substrate W has been placed on a predetermined substrate rest part to a cell controller CC corresponding to an adjacent cell, and the cell controller CC corresponding to the adjacent cell which has received the substrate W sends back information that it has received the substrate W from the predetermined substrate rest part to the cell controller CC corresponding to the original cell. Such transmission of information is conducted through the main controller MC. Each of the cell controllers CC sends information that a substrate W has been transported into a corresponding cell to a corresponding transport robot controller TC. The corresponding transport robot controller TC controls a corresponding transport robot to circularly transport a substrate W within a corresponding cell in accordance with a predetermined procedure (flow recipe). Each of the transport robot controllers TC is a control part achieved by a predetermined application operated on a corresponding cell controller CC.

As the unit controllers at the third level, a spin controller and a bake controller are provided, for example. The spin controller directly controls spin units (coating processing units and development processing units) provided in a corresponding cell, in accordance with an instruction from a corresponding cell controller CC. Specifically, the spin controller controls spin motors for the spin units to adjust the revolution per minute of a substrate W. The bake controller directly controls the thermal processing units (hot plates, cooling plates, heating units, etc.) provided in a corresponding cell, in accordance with an instruction from a corresponding cell controller CC. Specifically, the bake controller controls heaters internally provided for the hot plates, for example, to adjust the plate temperature and the like. An inspecting unit controller provided as a unit controller particularly in correspondence to the inspection cell directly controls the inspecting units (film thickness measuring unit 80, line width measuring unit 85 and macro defect inspecting unit 90).

As described above, the present embodiment reduces a controlling burden placed on each of the controllers with the three-level control hierarchy. Further, each of the cell controllers CC only controls a substrate transport schedule within a corresponding cell, without considering a substrate transport schedule within an adjacent cell. This lightens a transport-controlling burden placed on each of the cell controllers CC. As a result, the throughput of the substrate processing apparatus can be improved.

Next, the operation of the substrate processing apparatus according to the present embodiment will be described. First, a procedure for transporting a substrate W in the substrate processing apparatus will be described briefly. The substrate transport mechanism 12 of the indexer cell (indexer block 1) takes out an unprocessed substrate W from a predetermined carrier C, and places the substrate W on the upper substrate rest part PASS1. The transport robot TR1 of the BARC cell receives the unprocessed substrate W placed on the substrate rest part PASS1 using one of the holding arms 6 a and 6 b. Then, the transport robot TR1 transports the received unprocessed substrate W to any one of the coating processing units BRC1 to BRC3, which applies a coating solution for the antireflective film onto the substrate W while rotating the substrate W.

Upon completion of the coating process, the substrate W is transported by the transport robot TR1 to any one of the hot plates HP1 to HP6, where the substrate W is heated, so that the coating solution is dried and an underlying antireflective film is formed on the substrate W. Thereafter, the substrate W taken out from the one of the hot plates HP1 to HP6 by the transport robot TR1 is transported to any one of the cooling plates CP1 to CP3 to be cooled. At this time, the substrate W may be cooled by any one of the cooling plates WCP. The cooled substrate W is placed on the substrate rest part PASS3 by the transport robot TR1.

Alternatively, the unprocessed substrate W placed on the substrate rest part PASS1 may be transported to any one of the adhesion promotion processing units AHL1 to AHL3 by the transport robot TR1. The adhesion promotion processing units AHL1 to AHL3 perform a thermal process on the substrate W in an atmosphere of HMDS vapor to promote the adhesion of the resist film to the substrate W. The substrate W which has undergone the adhesion promoting process is taken out by the transport robot TR1, and is transported to any one of the cooling plates CP1 to CP3 to be cooled. Since the antireflective film is not formed on the substrate W which has undergone the adhesion promoting process, the cooled substrate W is directly placed on the substrate rest part PASS3 by the transport robot TR1.

Still alternatively, a dehydration process may be performed before applying the coating solution for the antireflective film. In that case, the unprocessed substrate W placed on the substrate rest part PASS1 is first transported to any one of the adhesion promotion processing units AHL1 to AHL3 by the transport robot TR1. The adhesion promotion processing units AHL1 to AHL3 perform a heating process (dehydration bake) on the substrate W just for dehydration without supplying an HMDS vapor. Upon completion of the heating process for dehydration, the substrate W is taken out by the transport robot TR1, and is transported to any one of the cooling plates CP1 to CP3 to be cooled. The cooled substrate W is transported by the transport robot TR1 to any one of the coating processing units BRC1 to BRC3, which applies the coating solution for the antireflective film onto the substrate W while rotating the substrate W. Then, the substrate W is transported by the transport robot TR1 to any one of the hot plates HP1 to HP6, where the antireflective film as an underlying film is formed on the substrate W by the heating process. Thereafter, the substrate W taken out from the one of the hot plates HP1 to HP6 by the transport robot TR1 is transported to any one of the cooling plates CP1 to CP3 to be cooled, and is then placed on the substrate rest part PASS3.

The transport robot TR2 of the resist coating cell receives the substrate W placed on the substrate rest part PASS3, and transports the substrate W to any one of the coating processing units SC1 to SC3. The coating processing units SC1 to SC3 apply the photoresist to the substrate W while rotating the substrate W. Since the resist coating process requires the substrate temperature to be precisely controlled, the substrate W may be transported to any one of the cooling plates CP4 to CP9 just before being transported to any one of the coating processing units SC1 to SC3.

Upon completion of the resist coating process, the substrate W is transported to any one of the heating units PHP1 to PHP6 by the transport robot TR2. The substrate W is heated in the one of the heating units PHP1 to PHP6, so that a solvent component in the photoresist is removed, whereby the resist film is formed on the substrate W. Thereafter, the substrate W taken out from the one of the heating units PHP1 to PHP6 by the transport robot TR2 is transported to any one of the cooling plates CP4 to CP9 to be cooled. The cooled substrate W is placed on the substrate rest part PASS5 by the transport robot TR2.

The transport robot TR5 of the inspection cell receives the substrate W with the resist film formed thereon placed on the substrate rest part PASS5, and transports the substrate W to the film thickness measuring unit 80. The film thickness measuring unit 80 measures the film thickness of the resist formed on the substrate W, thereby inspecting whether or not the resist film has a film thickness falling within a predetermined range. The substrate W which has undergone the film thickness inspection is taken out from the film thickness measuring unit 80 by the transport robot TR5, and is placed on the substrate rest part PASS7.

The transport robot TR3 of the development processing cell receives the substrate W placed on the substrate rest part PASS7, and directly places the substrate W on the substrate rest part PASS9. Then, the substrate W placed on the substrate rest part PASS9 is received by the transport robot TR4 of the post-exposure bake cell, and is transported into the edge exposure units EEW. In the edge exposure units EEW, an exposure process is performed on the periphery of the substrate W. Upon completion of the edge exposure process, the substrate W is placed on the substrate rest part PASS11 by the transport robot TR4. Then, the substrate W placed on the substrate rest part PASS11 is received by the transport mechanism 55 of the interface cell, and is transported into the exposure apparatus outside the substrate processing apparatus to be subjected to an exposure process for transferring a pattern thereto.

Upon completion of the exposure process for pattern transfer, the substrate W is again returned to the interface cell, and is placed on the substrate rest part PASS12 by the transport mechanism 55. The transport robot TR4 of the post-exposure bake cell receives the exposed substrate W placed on the substrate rest part PASS12, and transports the substrate W to any one of the heating units PHP7 to PHP12. The heating units PHP7 to PHP12 perform a heating process (post-exposure bake) for causing products generated by a photochemical reaction during the exposure to be uniformly diffused within the resist film. Upon completion of the post-exposure heating process, the substrate W is taken out by the transport robot TR4, and is transported to the cooling plate CP13 to be cooled. The cooled substrate W is placed on the substrate rest part PASS10 by the transport robot TR4.

The transport robot TR3 of the development processing cell receives the substrate W placed on the substrate rest part PASS10, and transports the substrate W to any one of the development processing units SD1 to SD5. The development processing units SD1 to SD5 supply the developing solution onto the substrate W to promote the development process. After a while upon completion of the development process, the substrate W is transported to any one of the hot plates HP7 to HP11 by the transport robot TR3 to be heated, and then transported to any one of the cooling plates CP10 to CP12 to be cooled. The cooled substrate W is placed on the substrate rest part PASS8 by the transport robot TR3.

The transport robot TR5 of the inspection cell receives the substrate W which has undergone the development process placed on the substrate rest part PASS8, and transports the substrate W to the line width measuring unit 85. The line width measuring unit 85 measures the line width of the pattern transferred to the substrate W which has undergone the development process to inspect whether or not the pattern has a line width that falls within a predetermined range. Upon completion of the line width inspection, the substrate W is taken out from the line width measuring unit 85 by the transport robot TR5, and is transported to the macro defect inspecting unit 90. The macro defect inspecting unit 90 inspects for the presence or absence of a relatively large defect (macro defect) appearing on the substrate W. Upon completion of the macro defect inspection, the substrate W is taken out from the macro defect inspecting unit 90 by the transport robot TR5, and is placed on the substrate rest part PASS6.

The substrate W placed on the substrate rest part PASS6 is directly placed on the substrate rest part PASS4 by the transport robot TR2 of the resist coating cell. Further, the substrate W placed on the substrate rest part PASS4 is directly placed on the substrate rest part PASS2 by the transport robot TR1 of the BARC cell. The processed substrate W placed on the substrate rest part PASS2 is stored in a predetermined carrier C by the substrate transport mechanism 12 of the indexer cell. A series of photolithography processes is thereby completed.

While the substrate processing apparatus performs the series of photolithography processes as described, each of the transport robot controllers TC and each of the unit controllers obtain processing history data. Processing history data is data of processing histories on a substrate W collected for each of the processing units and transport robots. Specifically, for instance, the transport robot controller TC for the BARC cell measures and obtains the transport time the transport robot TR1 consumes (the time elapsed between the receipt of a substrate W from a processing unit and the transport of the substrate W to a subsequent processing unit). The spin controller for the resist coating cell measures and obtains the processing time that the resist coating processor SC consumes. The processing time that the resist coating processor SC consumes includes both the processing time elapsed between the transport of a substrate W into a processing unit and the transport of the substrate W from the processing unit and the step processing time that respective process steps in the resist coating processor SC require. A process step is one step of processing performed in each of the processing units. In the case of the resist coating processor SC, the step of discharging the photoresist, the step of spreading the photoresist discharged onto the substrate W while rotating the substrate W, the step of reducing the revolution per minute to stabilize the resist film thickness are process steps, respectively.

Further, for instance, the spin controller of the resist coating cell obtains, for each process step, items such as revolution per minute of spin motors, ambient temperature, ambient humidity, flow rate of the photoresist, discharge pressure and airflow rate in the resist coating processor SC, as processing history data. The unit controller for the post-exposure bake cell obtains, for each process step, items such as light exposure, illuminance and circumferential moving speed in the edge exposure units EEW, as processing history data. Further, for instance, the bake controller for the resist coating cell obtains, for each process step, items such as plate temperature, cooling time and pressure in the heating units PHP1 to PHP6, as processing history data.

The processing history data containing items such as transport time, processing time, plate temperature, revolution per minute of spin motors and flow rate of solutions is transmitted from the transport robot controllers TC and unit controllers to the main controller MC through the cell controllers CC. Upon receipt of the processing history data, the main controller MC classifies the processing history data on each processed substrate W by each processing unit and each transport robot, and stores the classified data in the magnetic disk 99.

On the other hand, in the above-described transport procedure, all substrates W subjected to processing are transported to the film thickness measuring unit 80, line width measuring unit 85 and macro defect inspecting unit 90 to undergo the three types of inspections. Of the three types of inspections, the film thickness inspection is performed on a substrate W with the resist film formed thereon, while the line width inspection and macro defect inspection are performed on a substrate W which has undergone the development process. In the first preferred embodiment, the inspection block IB for performing these inspections is located between the resist coating block 3 and development processing block 4. Therefore, the film thickness inspection can be performed without going against the direction of transporting a substrate W before undergoing the exposure process from the indexer block 1 toward the interface block 5, and the line width inspection and macro defect inspection can be performed without going against the direction of transporting a substrate W which has undergone the exposure process from the interface block 5 toward the indexer block 1. A so-called sampling inspection in which some of substrates W subjected to processing are transported to the inspecting units may be performed, or only one or two of the three types of inspections may be performed.

In the present embodiment, when any one of the film thickness measuring unit 80, line width measuring unit 85 and macro defect inspecting unit 90 detects a substrate W with a process defect, the inspecting unit controller reports the detection of the defective substrate W to the main controller MC through a corresponding cell controller CC together with an identification code (wafer ID) of the substrate W. Upon receipt of such report, the main controller MC compares the processing history data on the substrate W detected as having a process defect with reference data. The reference data is operational data obtained when the transport robots and processing units operate normally, and falls within a predetermined range. The reference data is previously set and stored in the magnetic disk 99. The main controller MC judges whether or not the processing history data on the substrate W detected as having a process defect by each processing unit and each transport robot falls within the predetermined range set as the reference data.

As a result, a processing unit and a transport robot having processing history data that falls within the predetermined range set as the reference data are judged as normal. A processing unit and a transport robot having processing history data that falls outside the predetermined range set as the reference data are judged as abnormal. The processing unit or transport robot judged as abnormal and the identification code of a defective substrate W are displayed on the main panel MP. At this time, the processing history data on the defective substrate W may also be displayed on the main panel MP. An operator of the apparatus takes an action necessary for the defective processing unit or defective transport robot.

With such procedure, when a substrate W with a process defect is detected in the inspection cell, the location (processing unit or transport robot) which has caused the process defect can automatically be identified quickly and easily. Therefore, even when a process defect occurs, the time for stopping the apparatus for taking measures against the defect can be minimized.

Further, the sequential comparison between the processing history data obtained in detail for each processing unit and transport robot and the reference data enables accurate identification of the location which has caused a process defect.

Second Preferred Embodiment

Next, a second preferred embodiment of the present invention will be described. A substrate processing apparatus according to the present embodiment has the same construction and the same procedure for processing a substrate W as those in the first preferred embodiment. The second preferred embodiment differs from the first preferred embodiment only about the method of identifying an abnormal location when a substrate W with a process defect is detected.

That is, when a substrate W with a process defect is detected in the inspection block IB, the present embodiment assigns priority to making a judgment on the processing history data on a processing unit and transport robot previously associated with the details of that process defect over making a judgment on the processing history data on another processing unit and another transport robot. Specifically, when a substrate W having an abnormal film thickness is detected by the film thickness measuring unit 80, it is most probably resulted from abnormality of a processing unit related to the resist coating process, so that comparing the processing history data on the transport robot TR2 of the resist coating cell, the resist coating processor SC for performing the resist coating and the heating units PHP1 to PHP6 for performing heating after the resist coating with the reference data is given priority over making a judgment on the processing history data on another processing unit. At this time, the processing history data on the processing unit and transport robot given priority may be judged in more detail. Specifically, the processing history data containing a greater number of items (e.g., all items) than that in making a usual judgment as in the first preferred embodiment may be compared with the reference data. In the case where a substrate W is cooled in the cooling plates CP4 to CP9 just before the coating process by the resist coating processor SC, making a judgment on the processing history data on the cooling plates CP4 to CP9 is also given priority.

When a substrate W having an abnormal line width is detected by the line width measuring unit 85, it is most probably resulted from abnormality of a processing unit related to the post-exposure heating process, so that comparing the processing history data on the transport robot TR4 of the post-exposure bake cell and the heating units PHP7 to PHP12 for performing the post-exposure heating process with the reference data is given priority over making a judgment on the processing history data on another processing unit. At this time, the processing history data on the processing unit and transport robot given priority may be judged in more detail, as described above.

When a substrate W having a macro defect is detected by the macro defect inspecting unit 90, it is most probably resulted from abnormality present just before the exposure, so that comparing the processing history data on the cooling plates CP4 to CP9 for performing the cooling process before the exposure, the edge exposure units EEW, the transport robots TR2 to TR4 and the transport mechanism 55 with the reference data is given priority over making a judgment on another processing unit. At this time, the processing history data on the processing unit and transport robot given priority may be judged in more detail, as described above.

As described, when a substrate W with a process defect is detected in the inspection block IB, the second preferred embodiment assigns priority to making a judgment on the processing history data on a processing unit and transport robot having a close causal relationship with the details of the process defect. Therefore, the location which has caused the process defect can be identified more quickly.

Further, making a judgment in more detail on the processing history data on the processing unit and transport robot given priority enables strict judgment on the processing unit and transport robot which are most probably abnormal. Therefore, the location which has caused the process defect can be identified more accurately.

Third Preferred Embodiment

Next, a third preferred embodiment of the present invention will be described. A substrate processing apparatus according to the present embodiment has the same construction as that in the first preferred embodiment. The procedure for the photolithography processes on a substrate W in the present embodiment is generally the same as that in the first preferred embodiment, however, the present embodiment does not make an inspection on substrates W, but substrates W subjected to processing just pass through the inspection block IB. Therefore, in the present embodiment, a substrate W with a process defect is not detected in the inspection block IB.

In the present embodiment, the processing history data on all substrates W subjected to processing is obtained during the series of photolithography processes. Each time when the processing history data on a processed substrate W is obtained, the main controller MC makes a comparison between the obtained processing history data and the reference data. In short, in the present embodiment, the processing history data on all substrates W subjected to the photolithography processes is obtained and a judgment is made on the obtained processing history data.

When a processing unit or transport robot in which processing history data on a substrate W falls outside the predetermined range set as the reference data is detected, that processing unit or transport robot is displayed on the main panel MP with the identification code of the substrate W.

With such arrangement, a processing unit or transport robot which may cause a process defect can automatically be identified quickly and accurately.

Variant

The present invention is not limited to the above examples described in the preferred embodiments of the present invention. For instance, the main controller MC makes a comparison between the processing history data and the reference data in the above preferred embodiments, however, each of the unit controllers or each of the cell controllers CC may perform a judgment on the processing history data. Further, the substrate processing apparatus may be connected to a server dedicated to data collection, so that the server makes a judgment on the processing history data transmitted from the substrate processing apparatus.

In the third preferred embodiment, the processing history data on all substrates W subjected to processing is obtained and a judgment is made thereon, however, the present invention is not limited as such. The processing history data on an arbitrary number of a plurality of substrates W subjected to a series of photolithography processes may be obtained, so that a comparison may be made between the processing history data on the arbitrary number of the substrates W and the reference data. That is, a processing unit or transport robot which may cause a process defect is identified by a sampling inspection on the processing history data, so that the burden imposed on the main controller MC can be reduced.

The construction of the substrate processing apparatus according to the present invention is not limited to that shown in FIGS. 1 to 4, but various modifications are available only provided that a substrate W is transported to a plurality of processing units by transport robots and is subjected to predetermined processes. For instance, since no inspection is made on substrates W in the third preferred embodiment, the inspection block IB may be removed so that the resist coating block 3 and development processing block 4 are directly connected to each other.

While the invention has been shown and described in detail, the foregoing description is in all aspects illustrative and not restrictive. It is therefore understood that numerous modifications and variations can be devised without departing from the scope of the invention. 

1. A substrate processing apparatus for transporting a substrate to a plurality of processing units by transport robots to perform a predetermined process on the substrate, the apparatus comprising: a receiving element for receiving processing history data obtained during said predetermined process on said substrate, said processing history data including historical data about processing of said substrate collected for each of said transport robots and said processing units; and a defective processing unit identifying element for judging whether or not said processing history data received by said receiving element falls within a predetermined range which is previously set, to thereby identify a defective processing unit of said processing units or a defective transport robot of said transport robots.
 2. The substrate processing apparatus according to claim 1, further comprising: an inspecting element for making an inspection on a substrate which has undergone processing by said predetermined process or is on the way of being processed by said predetermined process, wherein when a substrate with a process defect is detected by said inspecting element, said defective processing unit identifying element identifies a defective processing unit of said processing units or a defective transport robot of said transport robots on the basis of said processing history data obtained when said predetermined process is performed on the substrate.
 3. The substrate processing apparatus according to claim 2, wherein when a substrate with a process defect is detected by said inspecting element, said defective processing unit identifying element assigns priority to making a judgment based on processing history data of one of said processing units and one of said transport robots previously associated with the details of said process defect over making a judgment based on processing history data of another one of said processing units and another one of said transport robots.
 4. The substrate processing apparatus according to claim 3, wherein when a substrate with a process defect is detected by said inspecting element, said defective processing unit identifying element makes a judgment based on processing history data of one of said processing units and one of said transport robots previously associated with the details of said process defect in more detail than on processing history data of another one of said processing units and another one of said transport robots.
 5. The substrate processing apparatus according to claim 1, wherein when a plurality of substrates are subjected to said predetermined process, said receiving element receives processing history data on all of said plurality of substrates, and said defective processing unit identifying element judges whether or not processing history data on all of said plurality of substrates falls within a predetermined range which is previously set.
 6. The substrate processing apparatus according to claim 1, wherein when a plurality of substrates are subjected to said predetermined process, said receiving element receives processing history data on an arbitrary number of said plurality of substrates, and said defective processing unit identifying element judges whether or not processing history data on said arbitrary number of said plurality of substrates falls within a predetermined range which is previously set.
 7. The substrate processing apparatus according to claim 2, wherein said predetermined process is a photolithography process, said plurality of processing units include: a resist coating processing element for applying a photoresist onto a substrate; and a development processing element for performing development of a substrate, and said inspecting element is located between said resist coating processing element and said development processing element. 